<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width,initial-scale=1.0">
  <title>my-project</title>
  <!-- 1. 外链式 -->
  <link rel="stylesheet" href="./style/link.css">

  <style>
    /* 2. 导入式 */
    @import url('./style/import.css');

    /* 3. 内嵌式 */
    div {
      height: 100px;
      width: 200px;
      border: 1px solid black;
      background-color: pink;
    }
  </style>
</head>
<body>
<!-- 4. 行内样式 -->
<div id="app"  style="width: 200px; height: 100px; border: 1px solid black; background-color: red;">
  css样式引入
</div>
</body>
</html>
